Train-lighting system



Jan. 1,1924

. J. A. CLARKE. JR.. ET AL TRAIN LIGHTING SYSTEM Filed July 15 1920 d. v Mg'r/Js R'Moody m 7 AITORNEY Patented Jan. 1, 1924.

UNITED STATES 1,479,171 PATENT OFFICE.

JOHN A. CLARKE, JR, QF EDGEWOOD PAR-K, PENNSYLVANIA, AND MORRIS R. MOODY,

OI DEER LODGE, MONTANA. ASSIGNORS 'IO WESTINGHOUSE ELECTRIC & MANU- FACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TRAIN-LIGHTING SYSTEM.

Application filed July 15, 1920, Serial No. 396,577.

To CAZZ whomit may concern:

Be it known that we, JOHN A. CLARKE,

Jr., a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania,

and Monroe R. MooDY, a citizen of the United States, and a resident of Deer Lodge,

in the county of Powell and State of Montana, have invented a new and useful Improvement in Train-Lighting Systems, of

which the following is a specification.

Our invention relates to train-lighting systems and it has special relation to the type of system wherein a motor-generator set is employed to supply lighting circuits and also to charge a battery. v

The object of our invention is to provide a system of the above-indicated character wherein a source of energy, such as a motorgenerator set drive-n from the supply circuit, is adapted to provide energy for a plurality of translating devices, such as a battery and a lighting circuit, together with a plurality of means, preferably in the form of variable resistors, for respectively regulatin the operation of both said devices and of on y one of them.

More specifically stated, it is the object of our invention to provide a system wherein a battery may be charged at a higher .voltage than the lighting-circuit voltage, the energy for both circuits being derived from the same generator, and the desired regulation being provided by means of a common resistor in both circuits and a second resistor in the lamp circuit only.

Another object of our invention is to provide a novel circuit arrangement whereby more lamps may be utilized, for a given voltage drop, than has been possible heretofore.

Our invention may best be understood by reference to the accompanying drawing, wherein the single figure is a diagrammatic view of a train-lighting system organized in accordance with our present invention.

Referring to the drawing, the system here shown comprises suitable main supply-circuit conductors respectively marked Trolley and Ground; a motor-generator set 1, comprising a driving motor 2 and a generator 3, together with a plurality of regulat ing means in the form of variable resistors 4 and 5, all of the foregoing elements being preferably located upon the electric locomotive that hauls the train, as indicated by the legend Locomotive. Each of the hauled coaches is provided with a lighting circuit or set of parallel-connected lamps 6, of a familiar form, and a storage battery B", which ma be employed for the usual pur poses, suc as furnishing energy to the lighting circuit 6 whenever the generator is inoperative for any reason. The lighting circuit 6 and the battery B located on a Pullman or other dicated by the legend Coach.

Each coach is also provided with the customary loop switch 10, which is closed whenever the generator is ino erative or when the coach is disconnected rom the 10- comotive, to complete the circuit between the negative battery terminal and the lamp circui a For the purpose of connecting the necessary circuits on the locomotive to the light ing circuit 6 and the battery B a multi' conductor jumper cable, of a familiar form, and containing three wires or conductors 7, 8 and 9, is provided between the locomotive anil the coach, as subsequently traced in detai The motor-generator set 1 comprises a motor or driving armature 12, of the com-' mutator type, which is preferably provided with a series-connected exciting field winding 13, a commutating field winding 14 and a separately excited field winding 15. The armature 12 and the field windings 13 and 14 are connected in series relation between the supply-circuit conductors trolley and ground. This circuit is the only circuit of relatively high voltage on the locomotive, since all of the other circuits to be described are energized from the low-voltage generator 3 or from a storage battery of comparable voltage. The field winding 15 is connected through a variable resistor 16 coach, as inacross a battery B which is floated acrossv the terminals of the generator 3 in accordance with a familiar practice and as subsequently traced in detail.

The generator 3 comprises a commutatortype armature 17 which may be rigidly connected to the motor armature 12 by means of a shaft 18. A pluralit of field windings 19 and 21 may be provi ed for the generator armature. One field-winding circuit is are preferably established from the positive terminal of the armature 17 through the commutating field winding 19, train-line conductor 22 and jumper conductor 8 to the coach conductor 23. The negative terminal. of the generator armature 17 is connected through conductor 2-1, variable resistor 5, conductor 25 and jumper conductor 9 to coach conductor 26.

The second field-winding circuit tor the generator is continued from the train-line conductor 22 through conductor 28, variable resistor 31 and field winding 21 to the nega- 'tive terminal of the armature.

The circuit of the shunt :tield winding 15 for the motor armature 12 is established from the train-line conductor through conductors 2S and 29, junction-point SO, where the circuit divides one branch including field winding 15 and variable resister 16 and the other branch including the battery B a common circuit being completed through conductor 27 to the negative terminal of the generator "mature 17.

The electric lamps in the coach are connected between conductors 23 and P10 the latter conductor being joined to the jumper conductor 7, whence circuit is continued through conductor 33, variable resistor i, conductor 3st, variable resistor 5 and conductor 524 to the negative terminal of the generator armature 17.

On the other hand, the coac 1 battery B is connected between conductors .23 and 26, corresponding to jumper conductors 8. and 9, and the circuit ol the battery B does not include the variable resistor 4-.

In other words, the resistor or regulating means 5 is common to both the li hting circuit and the battery circuit, whereas the other regulating means or resistor is connected in the circuit of the lamps 6 only. In this way, it is possible to impress any desired voltage upon the coach battery B to fully charge it, such voltage being regulated by means of the common resistor 5, while, at the same time, a desirably constant and lower voltage may be maintained upon the lighting circuit 6 by means of the variable resistor 1-,

In this way, the difference between the voltage of the battery B and the voltage impressed upon the lighting circuit 6 is absorbed by the resistor 4. Consequently, when the generator 3 is disconnected from the coach for any reason, the battery B furnishes the same voltage to the lighting circuit 6 as was obtained "from the generator 3 during normal running conditions.

In case the resistor 5 were included in the battery circuit rather than in the common circuit, it will be noted that a materially increased loss would occur whenever the battery was supplying voltage to the lamps, by reason of the presence of both resistors 4i and 5 in the circuit, and, moreover, a highervoltage battery would be required to furnish he desired lighting voltage, unless the resistor 5 were manually or otherwise cut out of circuit. On the other hand, by positioning the resistor 5 in thecommon circuit, no

lating operation, whereby more lamps may be utilized for a given voltage drop than would be possible with train-lighting systems embodying independent resistors for the lamp and the battery circuits.

This feature results from the fact that the coach battery B is connected to a point intermediate the resistors 4- and 5 and the current traversing the battery-circuit conductor 26 is thus dependent upon the difference of potential corresponding to the common junction-point of the resistors and the counterelectroinotive force of the battery.

As the number of lighted lamps is increased, the increased current drawn through the lamp circuit tends to correspondingly reduce the potential at the junction-point between the resistors. This drop in voltage would be proportional to the increase in load it a plain resistor, for example, were located in the position occupied by the battery B However, by reason. of the fact that the battery presents a certain counterelectromotive force in opposition to the generator voltage, it follows that the incipient drop of potential at the junction-point in question is checked because the current traversing the battery conductors 25 and 26 is also reduced as the potential in question diminishes.

Asa result, the final potential value at the junction-point is materially higher than would be the case if the battery B were not connected in the illustrated location.

In this way, it will be seen that the lamp load may increase without correspondingly decreasing the lamp circuit voltage, which will be maintained close to the normal value by reason of the decreased flow ofcurrent through the battery. However, such decrease of charging current is not detrimental to the operation of the battery for the reason that in actual practice the amount of charging current that traverses the battery over a long period of operation is sufficient to maintain it in a desirably charged condition. I

Not only may more lamps per volt drop thus be employed in connection with our train-lighting system, but a steadier load on the generator is maintained, which further tends to prevent flickering in the lamps.

WVe do not wish to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected Within the spirit and scope of our invention. For example, our invention may readily be employed in connection With an axle-driven generator, instead of a motor-generator set. lVe desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

We claim as our invention:

1. In a car-lighting system, the combination with a source of energy, a load, and a counter-electromotive force device, of means connected in circuit with said device and said load to prevent voltage variations on said load in proportion to changes thereof.

2. In a car-lighting system, the combination with a source of energy, a load, and a counter-electromotive force device, of a plurality of resistors connected in certain circuit relations with said device and said load to prevent voltage drops on said load in proportion to the increases thereof.

3. In a car-lighting system, the combination with a source of energy, a lamp circuit and a battery, of a plurality of resistors having a common junction-point connected to one terminal of said battery, whereby an increase of lamp load is partially compensated for by the concurrent decrease of current in said battery, to maintain a substantially constant lamp-circuit voltage.

In testimony whereof, I, JOHN A. CLARKE, J r., have hereunto subscribed my name this 23rd day of June, 1920.

JOHN A. CLARKE, JR.

In testimony whereof, I, MORRIS R. MOODY, have hereunto subscribed my name this 29th day of June, 1920.

MORRIS R. MOODY. 

